Adolescent drug use continues to be a major public health problem. The need for late onset drug prevention and early cessation in high schools is great, yet few universal programs exist that target alcohol, tobacco, and other drug use among high school students. Crossroads is a universal drug prevention program based on a cooperative relationship between high school peer educators, high school health teachers, and college mentors at the University of North Carolina at Wilmington. This is a multifaceted program that includes peer-led classroom sessions, school-wide social norms campaigns, school-wide drug information booths, and mentoring provided by college students at the Crossroads Prevention Center at UNC Wilmington. The infrastructure needed to organize all of these components and facilitate communication between all participants is provided by the Crossroads Web Site. This Phase II STTR has two objectives: 1) to refine all program materials and the web site based on lessons learned during Phase I and 2) conduct an independently evaluated randomized field trial to assess the effectiveness of the program. Crossroads will contribute to the shared mission of Tanglewood Research and the SBIR/STTR program to develop, test, and disseminate highly effective educational materials for preventing drug use among teens. This research project has the potential to improve the health and well being of high school students. In addition, it can inform the field of prevention regarding effective strategies for reducing drug use onset and encouraging early cessation among this under served group of young people.